WC-based cermet coatings were deposited by HVOF spraying in order to study the effects of laser remelting on coating microstructure, hardness, and dry sliding wear behavior. It was found that the laser treatment eliminates porosity and contributes to increased hardness and enforced metallurgical fusion between the coating and substrate, effectively improving adhesion and wear resistance.

In the continuous hot-dip galvanization process, the corrosion and chemical stability of the sink roll in the galvanizing bath are important issues that affect quality and productivity. In order to protect the sink roll, carbide cermet and/or ceramic coatings were deposited on the surface of the sink roll. The WC-, Cr 3 C 2 - cermet coatings were deposited by high velocity oxygen fuel (HVOF) spray, respectively. The coating samples were immersed in molten Zn-alloy containing 50wt.% aluminum at 833K for 24 hr and 144 hr, respectively. The inter-diffusion and inter-reaction of Zn, Al and elements in the coating and corrosion behavior of these coatings were investigated by XRD, SEM and EPMA, etc. The corrosion mechanisms of the carbide cermet coatings and ceramic coatings in molten High Al-Zn-alloy were proposed.